The subject invention pertains to new innovations in book binders and books made therewith. These book binders depart from known binder structures and concepts in several ways. First, the spine and the front and rear cover panels are an integral molding of a thermoplastic polymer, preferably low density polypropylene or polypropylene/polyethylene copolymers or mixtures. These polymers offer the advantage of forming living hinges by molding lines of weakness, e.g., a groove or two opposed grooves in the plastic matrix, and flexing the molding along the lines of weakness while it is still hot to cause molecular orientation of the polymer at the lines of weakness.
Second, the major part of the spine is a relatively thin, longitudinal, substantially planar panel extending transversely substantially the full distance between said cover panels when they are parallel and at right angles to the spine. Such spine then serves as the member to which the pages of the book are bound by fastening means, e.g., an adhesive but more preferably stitching or staples.
Almost all books with hard covers are bound by printing two, side-by-side pages of the book on one or both sides of a paper sheet, which is then folded vertically midway between the side-by-side printed pages. A number of these folded sheets are assembled in page number sequence, and the group of sheets are stitched at their collective fold lines to a spine backing by a vertical stitching line. Then another group of folded sheets, again with numerical page sequence, are assembled and stitched at their collective fold lines to the spine backing in a vertical line stitching next to the first stitch line. This process usually is repeated at least several more times until all pages have been stitched to the spine backing.
Third, the exposed, rear face of the spine has a large, longitudinal, shallow cavity, the bottom wall of which is the aforesaid panel to which the folded pages of the book are fastened. A molded spine insert can be press-fitted or otherwise mounted in the cavity to cover the exposed lines of stitching or the exposed parts of the staples lying in the cavity.